The present invention relates to a portable device for electronically locking and unlocking a specific lock through, for example, predetermined wireless communication, and to a mechanical key accommodated in the portable device.
Japanese Laid-Open Patent Publication No. 2000-320202 describes an electronic key system in the prior art. The electronic key system automatically locks or unlocks a door of a vehicle, such as an automobile, when a user carrying a portable device approaches a door. The electronic key system further permits the engine to start when the user enters the vehicle interior and sits on the driver seat. In this electronic key system, wireless communication is automatically established between the portable device and the vehicle. When communication is established, the electronic key system locks or unlocks the door and permits the engine to start. In detail, a controller of the vehicle transmits a predetermined request signal to the portable device in predetermined cycles to detect the position of the portable device. The portable device receives a request signal from the controller when the user enters a predetermined area around the vehicle, and transmits an ID signal containing an ID code, which is prerecorded in the portable device, to the controller. The controller compares the ID code of the portable device contained in the ID signal transmitted from the portable device with an ID code of the vehicle prerecorded in the controller. When the ID codes are identical, the controller automatically unlocks the door and permits the engine to start.
The portable device includes a case accommodating electronic circuits such as a transmission and reception circuits mounted on a circuit board and a battery for supplying power to the electronic circuits. The portable device performs wireless communication with the vehicle using power supplied from the battery. When the voltage of the battery decreases to a predetermined value or lower, that is, when the battery is drained, the portable device cannot perform wireless communication with the vehicle. This disables wireless control, which is executed through the communication, for locking and unlocking the door or permitting the engine to start. Wireless communication between the portable device and the vehicle may also be disabled when, for example, the portable device fails to function for one reason or another. In the prior art, to lock or unlock the door during an emergency, that is, when the portable device is drained or the portable device fails to function, for example, the portable device has a mechanical key for mechanically locking and unlocking the door. The user first operates an operation knob of a lock mechanism arranged in the case to unlock the mechanical key. The user then operates an operation knob arranged on the mechanical key to slide the mechanical key within the case until the mechanical key projects out of the case. The user mechanically locks or unlocks the door using the mechanical key in case of an emergency.
In recent years, portable devices have been required to be downsized to improve portability. However, in the conventional portable device described above, the lock mechanism for supporting the mechanical key is accommodated in the case of the portable device. Further, the operation knob of the lock mechanism, which needs to be wide enough to be operable by the user, is arranged on one side surface of the case. Such structural requirements restrict downsizing, and particularly, thinning of the portable devices.
Moreover, user awareness of security for vehicles has become high in recent years. Electronic key systems, which are highly secure and highly convenient since a mechanical key does not have to be inserted into a key hole, have become popular. As a result, portable devices for electronic key systems are required to be downsized and further required to have improved manufacturing efficiency. Mechanical keys for the portable devices are manufactured in processes separate from the processes in which main bodies of the portable devices are manufactured. Thus, the mechanical keys are also inevitably required to have improved manufacturing efficiency.